# US 10,863,921 B2 · Method and apparatus for determining a respiration rate of a subject > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,863,921 B2 - Document ID: US10863921B2 - Status: Granted - Kind: B2 - Application number: 15/775,096 - Filed: 2016-11-15 - Published: 2018-11-15 - Granted: 2020-12-15 - Earliest claimed: 2015-11-20 - Assignees: Koninklijke Philips N.V. - Applicants: Koninklijke Philips N.V. - Inventors: Ercan Ferit Gigi - Web page: https://patentgrep.com/patent/US10863921B2 ## CPC - A61B 5/0816: {Measuring devices for examining respiratory frequency (measuring frequency of electric signals G01R23/00)} - A61B 5/1135: {by monitoring thoracic expansion} - A61B 5/6823: {Trunk, e.g., chest, back, abdomen, hip} - A61B 2562/0219: Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract According to an aspect, there is provided a method of determining the respiration rate of a subject, the method comprising obtaining a signal from a sensor that is worn or carried by the subject; analyzing the signal to determine a plurality of values for a breathing-related feature; forming a histogram from the plurality of values for the breathing-related feature, the histogram comprising a plurality of groups, with each group having an associated count that is the number of occurrences of a value or values for the breathing-related feature corresponding to the group; applying a weighting to the count associated with each group to form weighted counts; and determining the respiration rate from a mean of the histogram with the weighted counts. ## Claims ### Claim 1 A method of determining the respiration rate of a subject, the method comprising: obtaining a signal from a sensor that is worn or carried by the subject; analyzing the signal to determine a plurality of values for a breathing-related feature; forming a histogram from the plurality of values for the breathing-related feature, the histogram comprising a plurality of groups, each group corresponding to one or more possible values of the breathing-related feature, with each group having an associated count that corresponds to the number of occurrences of a value or values for the breathing-related feature corresponding to the group; applying a weighting to the count associated with one or more of the groups to form weighted counts by determining the weighted count for each group by subtracting a threshold value from a respective count wherein weighted counts are set to zero in the event that the threshold value is equal to or greater than the respective count; and determining the respiration rate from a mean of the histogram with the weighted counts. ### Claim 2 (depends on 1) A method as claimed in claim 1, wherein the step of determining the respiration rate from the mean of the histogram comprises determining the mean of the histogram by: (i) for each group, multiplying a value for the breathing-related feature corresponding to the group by the weighted count for the group; (ii) summing the result of (i) for each group; (iii) dividing the result of (ii) by the sum of the weighted counts. ### Claim 3 (depends on 1) A method as claimed in claim 1, wherein the step of applying a weighting to the count associated with one or more groups comprises: applying a weighting such that the mean of the histogram is weighted towards the value or values of the breathing-related feature for the group having the highest count. ### Claim 4 (depends on 1) A method as claimed in claim 1, wherein the step of applying a weighting to the count associated with one or more groups comprises: applying a weighting such that the value or values of the breathing-related feature for the group or groups having the highest counts are emphasized in the mean of the histogram. ### Claim 5 (depends on 1) A method as claimed in claim 1, wherein the step of applying a weighting to the count associated with one or more groups comprises: discarding from the histogram any group having a count that is less than a threshold number. ### Claim 6 (depends on 1) A method as claimed in claim 1, wherein the step of applying a weighting to the count associated with one or more groups comprises: determining the weighted count for each group as the nth power of the respective count, where n is any number greater than 1. ### Claim 7 A non-transitory computer readable medium computer comprising a computer readable code embodied therein, the computer readable code being configured such that, on execution by a suitable computer or processor, the computer or processor is caused to: obtain a signal from a sensor that is worn or carried by the subject; analyze the signal to determine a plurality of values for a breathing-related feature; form a histogram from the plurality of values for the breathing-related feature, the histogram comprising a plurality of groups, each group corresponding to one or more possible values of the breathing-related feature, with each group having an associated count that corresponds to the number of occurrences of a value or values for the breathing-related feature corresponding to the group; apply a weighting to the count associated with one or more of the groups to form weighted counts by determining the weighted count for each group by subtracting a threshold value from a respective count; wherein weighted counts are set to zero in the event that the threshold value is equal to or greater than the respective count; and determine the respiration rate from a mean of the histogram with the weighted counts. ### Claim 8 An apparatus for determining the respiration rate of a subject, the apparatus comprising: a processing unit configured to: receive a signal from a sensor; analyze the signal to determine a plurality of values for a breathing-related feature; form a histogram from the plurality of values for the breathing-related feature, the histogram comprising a plurality of groups, each group corresponding to one or more possible values of the breathing-related feature, with each group having an associated count that corresponds to the number of occurrences of a value or values for the breathing-related feature corresponding to the group; apply a weighting to the count associated with one or more groups to form weighted counts by determining the weighted count for each group by subtracting a threshold value from a respective count; wherein weighted counts are set to zero in the event that the threshold value is equal to or greater than the respective count; and determine the respiration rate from a mean of the histogram with the weighted counts. ### Claim 9 (depends on 8) An apparatus as claimed in claim 8, wherein the processing unit is configured to apply a weighting to the count associated with one or more groups such that the mean of the histogram is weighted towards the value or values of the breathing-related feature for the group having the highest count. ### Claim 10 (depends on 8) An apparatus as claimed in claim 8, wherein the processing unit is configured to apply a weighting to the count associated with one or more groups such that the value or values of the breathing-related feature for the group or groups having the highest counts are emphasized in the mean of the histogram. ### Claim 11 (depends on 8) An apparatus as claimed in claim 8, wherein the processing unit is configured to apply a weighting to the count associated with one or more groups by discarding from the histogram any group having a count that is less than a threshold number. ### Claim 12 (depends on 8) An apparatus as claimed in claim 8, wherein the processing unit is configured to apply a weighting to the count associated with one or more groups by determining the weighted count for each group as the nth power of the respective count, where n is any number greater than 1. ### Claim 13 (depends on 8) An apparatus as claimed in claim 8, wherein the apparatus comprises the sensor.